There are a wide variety of devices on the market which are used for personal security. A partial list includes, a strobe light flash, a chemical spray, an alarm, and a high voltage stun device. The number of possible devices expands every year as new technologies develop.
The needs of the individuals who use personal security devices vary tremendously. A police officer may need a potent, but nonlethal, alternative to a handgun. A teen or senior citizen may need a device which will provide defense to an attack on their person. A security guard may need a combination of these security features. When personal preferences are also factored in, it is apparent that there is no one security device suitable for all needs.
The concept of a modular personal security device is known; having been disclosed in U.S. Pat. No. 4,716,402 granted to Francis in 1987. The Francis reference is primarily a room security device that is capable of playing a secondary personal security role. The problem with the Francis reference is that the components have minimal coordination and, as such, the device is more of an aggregation of features than a coordinated personal security device.